You've seen him in Jurassic Park and the fly. You may have posed for a selfie with the statue of him by the Thames this summer. But Jeff Goldblum has a hitherto little-known sideline as a jazz performer – and his debut album is out today. Kevin EG Perry meets Goldblum in LA to talk sex, drugs and underage jazz bar piano tinkling, and finds a man whose sense of wonder is utterly undiminished.